In a patient with diabetes mellitus, ambulatory infusion pumps have been used to deliver insulin to the patient. These ambulatory infusion pumps have the ability to offer sophisticated insulin delivery profiles including variable basal rates and bolus requirements. The ability to carefully control insulin delivery can result in better efficacy of the medication and therapy, and less toxicity to the patient.
Some existing ambulatory infusion pumps include a reservoir to contain insulin and use electromechanical pumping or metering technology to deliver the insulin via tubing to a needle and/or soft cannula that is inserted subcutaneously into the patient. These existing devices allow control and programming via electromechanical buttons or switches located on the housing of the device. The devices include visual feedback via text or graphic screens and may include alert or warning lights and audio or vibration signals and alarms. Such devices are typically worn in a harness or pocket or strapped to the body of the patient.
Some infusion pumps have been designed to be relatively small, low cost, light-weight, and easy-to-use. One example of such a pump is the OMNIPOD® insulin infusion pump available from Insulet Corporation. Examples of infusion pumps are also described in greater detail, for example, in U.S. Pat. Nos. 7,128,727; 7,018,360; and 7,144,384 and U.S. Patent Application Publication Nos. 2007/0118405, 2006/0282290, 2005/0238507, and 2004/0010207, which are fully incorporated herein by reference. These pumps include insertion mechanisms for causing a transcutaneous access tool, such as a needle and/or soft cannula, to be inserted into a patient. Although such pumps are effective and provide significant advantages over other insulin infusion pumps, there is a need for continued improvement.
Complications arising from diabetes mellitus may be reduced by careful management that includes regular checking of glucose concentration levels, typically at numerous times of the day depending on the specific type of diabetes mellitus, with Type 1 patients generally having to check glucose levels more often than Type 2 patients.
Most diabetes patients rely on glucose strips along with hand-held glucose meters that record glucose levels in blood drawn via finger pricking, which may be referred to as user-dependent (self-monitoring) of blood glucose. However, the pain associated with finger pricking, together with the inability of test strips to reflect whether the glucose level of a patient is increasing or decreasing at any point in time with user-dependent (self-monitoring) of blood glucose level is problematic.
Continuous glucose monitoring incorporated into an ambulatory infusion pump may be beneficial to patients by eliminating many of the problems associated with self monitoring, as well as help identify glucose trends to physicians who may then better optimize treatment plans. Furthermore, it would be beneficial for such devices to confirm actual delivery of the medication.